This invention relates to large, up to 500 kiloton, forging presses and, more particularly, is directed to a novel tie-rod beam construction from which a frame for the forging press may be assembled.
The present application is closely related to the subject matter described in patent application Ser. No. 821,790 entitled "A FORGING PRESS WITH ADJUSTABLE DAYLIGHT AND WITH YOKE DESIGN FOR ATTACHING TIE-RODS TO CROSSHEADS" which is commonly assigned with the present application. The subject matter thereof is incorporated herein by reference.
As is known and by way of background, forging presses are used for shaping metal slabs into end products of desired shape by pressing the metal slab between a pair of dies to give it its shape.
Structurally, the forging press includes a very large steel frame which surrounds a stationary bridge or platform on which a workpiece is placed. In a particular type of a forging press known as a pull-down press, the frame is movable up and down relative to the stationary bridge. The frame is actually a massive structure which includes a horizontally extending upper crosshead which is disposed transversely to the stationary bridge, a lower crosshead below the bridge and a pair of tie-rod assemblies on either side of the bridge for connecting the upper crosshead and the lower crosshead to one another. The upper crosshead of the frame is used for squeezing the workpiece between the frame and the stationary bridge. Very powerful hydraulic jacks located underneath the bridge are operable to push the lower crosshead of the frame downwardly, thereby producing enormous compressive forces on the workpiece which is located on the bridge directly underneath the upper crosshead of the frame.
The tie-rod assemblies which connect the upper and lower crossheads to one another are in a mechanical stress environment too large to make it practical to construct an entire tie-rod assembly as a single unitary component for several reasons. For example, the mechanical stresses are so large that the weight of each of the two tie-rod assemblies exceeds two thousand tons. Available steel industry facilities cannot produce a single large steel beam or bar which will handle such a load. Moreover, it is highly impractical to ship very large and heavy structures. Furthermore, the length of a tie-rod is dictated by requirements of the particular forging press and flexibility in tie-rod lengths is desired. Other reasons include repairability and maintenance of the forging press.
In consequence of the above considerations, it has been known to construct a tie-rod--or for that matter a crosshead--as laminated assemblies constructed of superposed, rolled steel plates or beams with a combined mechanical strength which meets the requirements of the press.
Particularly in relation to the design of up to 500 kiloton forging presses, there is a clear and present need for improved tie-rod plates or beams which are better able to handle the very large forces of the press while maintaining weight and cost at a minimum.